Printing ink, process of printing, and article for use therewith



Patented Aug. 14, 1945 PRINTING INK, PROCESS OF PRINTING, AND

, ARTICLE FOR USE THEREWITH Jos ph G. Gurado, Ru h rf rd, N- L, assignorfto Gen ral P nt n Ink C rnora iomNcw 101 5 N. Y a corporation of Delaware No Drawing. Application July 24, 1941,

Serial-No. 403,869

13 Claims.

This invention relates to a method for pro vide a method and means for impressing characters on organic plastic materials of the type of cellulose acetate, by means of a typewriter.

A further object of the invention is to provide a method for typin on transparent organic sheet materials, characters of .such sharpness of definition and opacity to light, that they may be used in projection apparatus for throwing printed matter on a screen or other light inter cepting surface. s

A still further object of the invention is to provide a typewriter ribbon so treated that it will not dry out or set on standing at room temperatures for long periods, but which will imprint characters upon non-porous synthetic organic materials of selected characteristics, which will dry very rapidly when typed, and which will be clear out, intense and legible at magnifications of the order of 5 to 10 times when projected onto, a screen or other surface,

For many purposes, in furnishing news or other information such as stock quotations and the like, to assembled crowds, it has been 'customary to project this information onto a screen, orother light intercepting surface, using transparent, typed or printed sheets through which the light passes except where obscured by the printed characters.

In preparing such printed surfaces for projection, it has been the practice in the past to type on glassine, i. -e., a transparent paper material, with ordinary or specially prepared typewriter ribbons. The results thus obtained have never been entirely satisfactory, as the glassin-e was not completely transparent, and moreover was extremely brittle and su ject to breaking in the projector mechanism and up n handling. Furthermore, such practices would not obtain a clean cut, sharp print, which would be su-fficiently intense and opaque, and which would set immediately upon typing. The same objections obtained when re enerated cellulose material (Cellophane) was .used.

The recent introduction of television has increased the demand for a clean cut, sharp and opaque typed print on transparent material which can quickly and easily be produced by means of typing in an ordinary typewriter. In

to hold and read from aftyped script 38 119131 18 present practice in ordinary? broadcastingm By the use of thepresent' invention the script maybe typed on transparent material and'projected onto a screen outside the range of the-picture being broadcast, but Withinthe' line: of visionzof the television actors. In typing upon paper or the like using'an ordinary typewriterribbon, the ribbon inkmaterlal' must not only remain sufficiently non-solid or' fluent at room tempera: tures under the ordinary conditions iof use, '-bu,t it must transfer an impression which will dry or set so as to be smudge proof almostz immediately on transference; This-can bel"accomplished readily enough for printingon paperand other relatively absorbent materials, by using-- extremely'high boiling solvents such'as glycerin;

which are practically non-.volatile even at-elefibers of the sheet by-the'impact'. of the/type element.

However, on'such n on=porous materiais-Ias glassine, regenerated cellulose and other "trans parent, non-absorbent sheets, their non-absorbency has practically prevented'the obtaining of dry, smudge proof characters of sharp definition suitable for use inprojection. 'As the sol-vent could not penetrate it tended readily to'smear out beyond the outline-of the printed characters upon the impact of the typ and-would readily smear on contact. Also such prints whenobtained are'of low intensity'containingrelatively low concentrations 01. opaque coloring materials. In typewriter ribbonink 'the'percentage of color, including both pigment and idyepranges from concentrations of around 5% or below; .to a few containing as high as 20% coloring "matter. This higher figure represents about the-maximum percentage of coloring matter whic-his incorpora-ted into a' typewriter ribbon ink material, even in cases where no'bin'de r or thickening-material is used. Besides being unsatisfactory in failing to produce a clear sharp p'rint, 'StlCh'Tmaterialsyfurther'fail to-proyide' enough opacity for the projection desired :by me. I 1

I have-now discovered that the'se 'diffi-culties, .of lack of sharpness 'o'f"definition -and :lack-'o"f opacity and intensity of the print, can be'overcome in the practice bf my invention by using a transparent sheet materiaL' which is'so'luble "in, or softened by, the vehicle used for' the ink :material to be transferred thereto. Thus'bythe television broadcasting m are t, permitted .55 use of certain orgam'c' olyents andcertain trans;

parent sheet material each selected with respect to the other and having coordinated characteristics of intermaterial responsiveness I can prepare a typewriter ribbon impregnating compound whose vehicle has the required sheet solubility, and also possessesthe necessary evaporation and other characteristics for setting. I can thus produce a transparent typed material which will dry almost immediately upon typing and which will l o be smudge proof in use, and'moreover willhave the clear definition necessary for projection'by, strong light sources on screens and the like.

I have found that only those transparent, 'iganic materials may be used for the sheet, wh

are soluble in, or are softened by solvents which combine the necessary evaporation rates and the mutual solvent power for my purpose. Examples acidity, and in which I am able to incorporate high intensity, opaque coloring materials in extraordinarily high proportionsfar greater than has previously been considered'the maximum possible quantity. I

As the vehicle, I use a solvent or softening agent for the particular material on which the typing is carried out. This allows penetration or bondin or solution-admixture of the solvent into and upon the base to cause the ink to dry or set: with sufflcient rapidity, and also servesto utilize .a portion of the printed surface as a binder material for the color, and to prevent the spreading and smudglng so often present in typewriter ribbon pastes especially'when attempt is made to use on non-absorbent surfaces. The solvent must have a high enough boiling point so that the ribbon will not dry out on:standing at room temperatures, under the conditions of use. Furthermore, its boiling pointmust not be so high that it will completely resist evaporation when typed, as such a solvent will deposit a film which will smudge after typing. r I

The vehicle, besides being a solvent or softening agent for the basic sheet materiaL-is also an exceptionally good solvent for the intense, oil soluble dye materials so as to produce an opaque print which will obscure the strong light of the projecting source.

I have found that suitable from the point of view of non-drying, are in most cases too low in solvent power either for the dye material or the transparent sheet material; and, inzgeneral, solvent power decreases with increase in boiling point of the material selected. This solventpower must be present in the heretofore unattainable amounts, sufiiciently high amounts for the intense dyes such asmethyl violet base being needed to impart the required opacity.

The efiort to use solid pigments in substantial quantity to increase opacity creates a print which is fuzzy and indistinct; in outline, especially noticeable when the letters are magnifiedin projection.

Because the maximum quantity of coloring material was limited in the case of pigments by the thickening action and fuzzy prints caused thereby, and in the case of dyes by their limited solubility in the materials used, substantial practical operating limitations and objections were inherent in attempted uses as described. I have now discovered that a solvent may be used which is initially a relatively'good solvent for the intense dye base, and which is acidified, slightly, so that it has a pH value as measured by the Beckman pH me- "ter using a glass electrode with a calomel reference electrode of around 3.03 or below, and that with such the amount of the dye material which i can be effectively incorporated is nearly doubled.

Although many commercially available solvents are" acid in pH I have discovered the surprising of mutual solvent properties, evaporation rate and the higher boiling solvents.

fact that such usual and incidental acidity is not enough, but it is only after the pH is reduced to the pH around the figure named (i. e. about 3.03),

or below, that the necessarily large increase in dissolving power is attained. For example, a sample of commercial carbitol acetate as received when tested had a pH of 3.12 and yet was found entirely unsatisfactory in the high solubility characteristics, being capable of dissolving only about 15% of methyl violet base, a quantity in theneighborhood of the prior art maximum quantities. But when suflicient acid was added to reduce the pH to 3.03 the solubility suddenly increased enormously, so that it was then possible to incorporate nearly 40% of-the dye. Greater additions of acid increased the solvent'power and permitted the incorporation of additional amounts of the dye, but such additions increased the viscosity until finally impairing the penetration characteristics needed for the ink material to penetrate and soak into the ribbon. Added solvent power attending added acidity thus should be so limited that the viscosity, impregnating and other characteristics'required in the ribbon impregnating compound will still be present. Concentrations of about 30% or mor of dye in my paste produce prints which are quite satisfactory from the point of view of opacity. However, I prefer to use concentrations between about 35 and 40% to give a satisfactory viscosity range, together with the desired opacity. Such die additions, to produce the desired color intensity, aifect the viscosity which increases as the per centage of dye in the solvent increases, and I have found that in such high concentrations no binder can be used because of the limitations imposedby the working viscosity required. Without such binders dye solutions in the solvents which I employ, having concentrations sufficiently high to give the intensity and opacity necessary to fulfill the requirements of my invention, have viscosities so high as to be at about the upper limit of good working, qualities; and any addition of binder raises the viscosity still further and makes the ink too viscous for use. Thus inks containing binder, and within the working limits of a typewriter ribbon, can be produced only by a sacrifice in the dye used. This, however, renders the resulting prints less eifective for my purposes, and even too light for projection purposes. In my ink a binder is not necessary as the print when applied to the soluble base dissolves sufficient of the binding material of the base to insure strong adherence and binding of the material of the print to the base; and I have found the surprising result that by the use of my invention I can make a legible print which is adequately displayed by reflected light as well as by transmitted light, the shadowcast in the latter event being satisfactory for projection.

For imparting a desired body to my paste. I may include a small quantity of an inert filler l I v V p Whiei my enepme to fine nec ssary 'r'zteh't b? virtue 5r itseol jehp rower rdrphe base, and 'ilth'dfigh may very plight vabpration i's requiem '11; mar

sary for a sm dge proof impression. I hhfe f'o'iih'ii that only sl'Vnts 91, dscribed and. boiling within a very narrow range of boiling points can be used. I have found boiling points between about 75 266* a 225* 0;, w be satisraet arv with; 501- vrii T Hie sbi'vnt btiwf and aidifiy or ifi'vhi'iifihffiiid; afiher satisfaetary dyes' ir'i may heir i: the iiieiifiyl vio'lefi prev ousl mentiqned, ere Vifdii; blue biS; nirdsirie b'as'e aria m= diiliii' I H fbrebai pas't' by first acidifying the sap-- ve t 136 231; 530i about 3.63, with any suita le afganic aia, for exar'rim eeetie, t en ii-seeming the (1% iii the sifli iit'; I tliii' add any degree iffibiint of pigmeni: 6r cith'ef iiieff, puwa-r or fine-r gring' in any siimebiemn such a bail min, r'bilr miil or the iiritil adequate; ie-

i s dbiiainti. The typewriter ri-bbcm than ihiprgnateq withji' pasfie for igemp by passin the iibb'dh tnreugh a balt li ofth' hiizifiiir are suitable pei 'npratur'e, and gently queez i ig 01f the excsgbetween squeeze ran ers; 0r S'ifiiiiai' or, the paste maybe applie bye; Wick m chanim orpthegmea s. '3

Wile-h iiji iris' are mad with his ribbdn on trensiigint, iidii bdibiisfsh'e'tsl of siih character as id be sari'iauy diss'cilvediir softened by 'sb vent 150mm 6f the Vehil, blfegh cut, aensge, 'pb'aici e irfibre's'ibneare pro uce which Yield dark, legible dfii'ac'trs' when siibje'ciie' 'd t6 pi'bjbtifdfibfi it fireeii by pa's'i'hg light through the tr'ahsiadr'eht bbrisi'pn, even when subh project-inn takes place at; hih magmficati he I e typewriterribbon thu spr'epa'red will rer aih suitably moist aha 'u'fsable in a'typewi'iter for rasbiiablj long periods of use, blit if the ribbc m s are tp be 'stg'ird 0r kept in stock for a15- iiiqi'jal'ffl'e 'peribds before rise, the? may be kept in air tihiz ontaihers t6 retard even that/Smell ambuht pf vpi 'ratidn which taker; place at robin teiriperfiires'. Als'bit may be used for printing oh igequred brsynthti resincoalted paper, on plfastifgfs iiri rnb'i'st'ur 'pfic'if Cellophane -(a labqiiei'ed iegener'lqtea cellulose), and 'synth'eti resins 6f the alkyd, urea fqrmaldehyde, vinyl ghafmany ether f'y'pes or rsin's 'ahd other suriir. M hire' the bro'due't herein described andizhe tfiod or prim ng or typing with it constitute preferred embodiments (yr the invention it is to b iihdrstbiid 'thas the invention is n01; limilfid t'f) this precise bi'de's aim. product, and that c' hefri'ges may be ri ad'ethrein without departing If'r m 'the Scope of the invention as described ehfi What is claimed is V v 1. tfi'hlwr i'ter ribbbn 'of the character de- Sg'frib'd, edafated to tralnefer "sharply defined, opaque, hqnejsrhfid'gihg characters to 'a nompop' 'bfiS Qrgriic material Having solubility characifiortiiniteq with the character of the p irflej, inediu'm applied, Cb'rnprising a web ma.-

' te r1,i impregnated with an opa'q'lie printing CbmipQeitidn 'binbrisin 'a, liquid, Said liquid being of pH not t6 "exceed about 3.03, 'a'fi'd which is substantiglly nqn evaporgtin at r'din temperatures gag 'gw rii izi ag ajbbnmg range between about 200 C. ahd 225 C. and which ha a predeterxififieai rare bi penetratin 6r solv nt action upon sga d Org'airiiq material when ipblied thereto as deiinaiied Ch'arecters faint} has Of the order of 30% 10f a 'dissolv'ed, high intensity dye .base, Where-b? ilpid setting bf the printed characters 2. A typewriter ribbei bffth'e c'h arater demedium applied, comprising a web material impregnated with a composition comprising a soluble dye base and a liquid, said liquid being of pH not to exceed about 3.03, and which is substantially non-evaporating at room temperatures and which has a boiling range between about 200 C. and 225 C. and which contains in excess of about 30% and not more than about 40% of said dye base dissolvedtherein, and which composition has a predetermined penetrating or dissolving action upon the organic material when applied thereto as delineated characters, whereby rapid setting of the printed characters tosharply delineated, smudge-proof condition is effected,

3. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging aracters to non-porous organic material havin solubility characteristics coordinated with the c aracter of the printing medium applied, comprising a ribbon-like fabric material impregnated with an opaque printing composition comprising in excess of about 30% and not more than about 40% of methyl violet, dye base dissolved in a liquid said liquid being of-pH not to exceed about 3.03 and which is substantially. nonevaporating at room temperatures and has a boiling range between 200 C. and 225 0., and which composition has a predetermined rapid rate of penetrating or dissolving action upon'the organic material when applied thereon as deprinted characters to a sharp, definitely opaque smudge-proof condition is effected.

4. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging characters to non-porous organic material having solubility characteristics coordinated with the character ,of, the printing medium applied, comprising a ribbon-like fabric material impregnated with, an opaque printing composition comprising methyl violet dye base in excess of and not more than about 40% dissolved in a liquid, said liquid being of pH not to exceed about 3.03, and which is substantially non-evaporating at room temperatures and has aboiling range between 200 C. and 225 C., and which composition has a predeterminedrapid rate of penetrating or dissolving action upon the organic material when applied thereon as delineated characters, whereby rapid setting of the printed' characters to a sharp, smudge-proof condition is effected. I a

5. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging characters to a non-porous, transparent organic material having solubility characteristics coordinated with the character of the printing medium applied, comprising a 'fabric material impregnated with a composition comprising carbitol acetateacidified to a pH of about 3.03, and methyl violet dye base in excess of about and not more than about 6. An ink material of the character described, adapted to be printed uponta transparent base, comprising an organic solvent for the base having a boiling point betweenabout 200. C. and 225 C., and a pH value not exceeding about 3.03; methyl violet dye base in quantities in excess of about 30% and not more than about 40%.

"7. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging characters to a non-porous transparent organic material having solubility characteristics coordinated with the character of theprinting lineated. characters, whereby rapid setting of the K medium applied, comprising a, fabric material. impregnated with a composition comprising carbitol acetate acidified to a pH of about 3.03, and methyl violet dye'base in excess of 15 and not more than about 40%. r I 1 8. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging characters-to a non-porous transparent organic material having, solubility characteristics coordinated with the character of theprinting medium applied, comprising a fabric' m aterial impregnated with a composition comprising carbitol acetate acidified to a pH of about 3.03, and methyl violet dye base in an amount of the order of 30%. h

9. A typewriter ribbon of the character described, adapted to transfer sharp, non-smudging characters to transparent cellulose acetate sheeting, comprising a web material impregnated with,substantially large quantities of an opaque printing composition co'mprising a liquid, said liquid being of pH not'to exceed about 3.03, and being substantially non-evaporating at room temperatures and having a boiling range between about 200C. and 225 C., and ofgthe order of 30% of an intense dye base dissolvedtherein, and which composition has'a predetermined rapid rate of penetrating or dissolving actionon'tlie cellulose acetate when printed thereon, whereby rapid setting of the printed characters to asharp; smudge-proof condition is effected.

' '10. A typewriter ribbon of the character described, adapted ,to transfer sharp,,non -smudging characters to transparent vinyl resin polymer sheeting, comprising a web material impregnated with. substantially large';quantities, of. an opaque printing composition comprising a liquid, said liquid being of pH not to exceed about 3.03 and being substantially non-evaporating ,at. room temperatures and having a boiling range between 200 (Land 225? Q, and of'the order of 30% of an intense dye base dissolvedtherein, and which composition has apredetermined rapid rate of penetrating or dissolving action on thevinyl resin polymer sheeting whenjprintedj thereon, whereby rapid setting of the printed characters'to a sharp, smudge-proof coriditionis effected. I

I 11. An ink material of the character described, adapted to be printed upon a transparent base, comprising an organic solvent'for the base having aboiling point betweenabout 200 C.,and,225 ,C., and a pH value not exceeding about 3,103; methyl violet dye base in quantity in excess of, about 30% and not more than about 40%, and a small pro: portion of a finely divided inert solid'inaterial.

12. An ink material of the character described, adapted to be printed upon a transparent base, comprising an organicsolvent for the base having a boiling. point between about 200? C. and 225 C,, and a pH value not exceeding about.,3.03; methyl violet dye base in quantity in excess of about 30% and not more than about 40%, and a small proportion of carbon black.

13. An ink material of the character described, adaptedto be printed upon: a transparent base,

comprising. an organic solvent for the base having a boiling point between about'200 c. and225 c.,

and a pH,value not exceeding about 3.03, anda methyl'violet dye base inquantities in excessof about 15% andnot moretth anabout 40%, and a small proportionof a finely divided inert solid material. J OSEPH G. CURADO. 

